Dynamic Behavior of Railway Vehicle Having a Clearance between Wheel and Axle in Rolling Direction

This paper deals with a rail vehicle the wheelset of which has a clearance in the rolling direction. Numerical simulation is employed directly considering the clearance, which exists in the spline between the wheel and the axle, to analyze the dynamic characteristics. Simulation results show that the existence of clearance makes the wheelset rolling vibrate in a limit cycle oscillation. Then, generation mechanism of the limit cycle is investigated as well as the influence of the expanded clearance, which is due to the wear and deformation by long-term use, on the limit cycle. Moreover, it is shown that the use of higher equivalent conicity of wheel tread is desirable to reduce the flange contact by the limit cycle oscillation under existence of track irregularities.